There's a program called Keyhole TV that you can download to watch it. If you don't want to do that, there will be other various streams out there. Just check back here and you'll find a link to one.
Also, if you plan to watch it live, watch a half hour early (at 4/7). The announcement isn't likely to happen until the end of Pokemon Smash, but they might announce it earlier. --- THAT'S MISS HOME ROWED TO YOU eyes glazed like a mirror to heaven
Keep in mind, they said that it would be announced in all (relevant) languages on the same day, so you don't necessarily have to watch a stream of a Japanese show. --- Socran's Razor: "Never attribute to massive stupidity by someone else, what could be explained by a tiny bit of stupidity on your own part."
Correct. While Smash will get the news first, once the show ends the US site will post about it, giving us localisations etc.
Really, there's no point in watching it if you don't understand it. If you must see it the instant it comes, then the websites around the net will post it in no time, with translations --- Serebii from the amazing Serebii.net Your #1 Source for ALL Pokémon Games & Anime info as the top online Pokédex & Attackdex!